The KF VS57 is used in conjunction with a mount bracket that has a spring loaded tension arm and pulley attached. Is this present on your unit? Also, there's a special carb and enclosure, as well as a unique harmonic balancer assembly. If you have everything, as well as the air cleaner and special Carter fuel pump that was used on the 54-5 cars, and the S/C is in working order, they can command several hundred dollars. If all you have is just the blower unit, perhaps $250, give or take a few bucks. Units that are stuck will require a rebuild kit that runs about the same. Having one professionally rebuilt, the last I checked, ran about $750.
There is a VS57 on ebay right now and it's priced at $2000. The seller is overpriced by a factor of about 10.
